/*
 * Copyright 2011 Tom Gibara
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0

 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */
package com.tomgibara.crinch.hashing;

import com.tomgibara.crinch.util.WriteStream;

public abstract class SeededHashSource<T> implements HashSource<T> {

	private final HashSource<T> source;
	
	public SeededHashSource(HashSource<T> source) {
		if (source == null) throw new IllegalArgumentException("null source");
		this.source = source;
	}
	
	public void sourceData(T value, WriteStream out) {
		seed(out);
		source.sourceData(value, out);
	}
	
	protected abstract void seed(WriteStream out);
	
}
